Apparatus for reducing combustor exit duct cooling

An apparatus for reducing the cooling requirements of a combustor exit duct in a gas turbine engine, the combustor including a combustion chamber defined by at least an outer annular wall and an inner annular wall, the combustion chamber communicating with a transition duct having a first duct portion having an outer duct wall and an inner duct wall, said combustion chamber being surrounded by an annular passage for providing cooling airflow to the inner and outer walls of said combustion chamber, an engine component downstream of said first duct portion and upstream of a turbine section, the engine component including a plurality of stator vanes for guiding gases through said gas turbine section with said engine component defining an inner ring and an outer ring;

• said inner ring of said engine component being connected to a static support;
• said outer ring of said engine component including a circumferentially extending shroud which is integrally cast with a portion of the inner duct wall of said first duct portion,
• the improvement including a second wall spaced from the inner duct wall and co-extensive therewith, the second wall being in the annular passage and including a plurality of openings therein to permit impingement cooling of the inner duct wall.